:root{--bg:#F5F7F8;--paper:#FFFFFF;--ink:#172B3A;--text:#344454;--muted:#586B78;--line:#D7E1E6;--primary:#176B6A;--primary-hover:#125655;--accent:#176B6A;--soft:#E8F4F2}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}h1,h2,h3{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);line-height:1.18;font-weight:650;margin:0 0 16px}h1{font-size:clamp(2rem,4vw,3.25rem)}h2{font-size:1.8rem}h3{font-size:1.35rem}p{margin:0 0 16px;color:var(--muted)}a{color:inherit;text-decoration:none}a:hover{text-decoration:underline;text-underline-offset:4px}button,a,input,textarea,select{touch-action:manipulation}button{cursor:pointer;font:inherit}a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--primary);outline-offset:4px}.shell{max-width:1220px;margin:auto;padding:0 32px}.stack{display:grid;gap:18px;align-content:start}.stack>p,.stack>h1,.stack>h2{margin:0}header{border-bottom:1px solid var(--line);background:var(--paper)}.topbar{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:84px}.brand{font-size:1rem;font-weight:750;letter-spacing:.14em;text-transform:uppercase;color:var(--ink)}.nav{display:flex;gap:26px;align-items:center}.nav a,.nav button,.mobile-nav button{font:inherit;color:var(--muted);background:none;border:none;padding:0}.menu-toggle{display:none}.mobile-nav[hidden]{display:none}main{padding:40px 0 80px;min-height:75vh}.panel{background:var(--paper);border:1px solid var(--line);padding:28px;margin-bottom:24px;min-width:0}.kicker{font-size:.72rem;font-weight:700;letter-spacing:.13em;text-transform:uppercase;color:var(--accent);margin-bottom:12px}.button{display:inline-flex;align-items:center;justify-content:center;gap:22px;min-height:46px;padding:10px 20px;border:1px solid var(--primary);background:var(--primary);color:#fff;font:600 .9rem/1.4 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;border-radius:2px;text-decoration:none}.button:hover{background:var(--primary-hover);text-decoration:none}.button.secondary{background:var(--paper);color:var(--primary);border-color:#B5C9CD}.button.secondary:hover{background:var(--soft)}.actions{display:flex;gap:14px;flex-wrap:wrap;align-items:center}.text-link{color:var(--primary);font-weight:600;font-size:.9rem;text-decoration:underline;text-underline-offset:5px}.meta{font-size:.85rem;color:var(--muted)}.welcome{padding:28px 0 64px;margin-bottom:36px;border-bottom:1px solid var(--line);position:relative}.welcome h1{font-size:clamp(2.3rem,4.6vw,3.8rem);max-width:730px;line-height:1.1}.welcome p{max-width:570px;margin:24px 0 30px}.welcome-mark{position:absolute;right:25px;top:30px;width:230px;height:260px;display:grid;place-content:center;text-align:center;color:var(--muted);border:1px solid var(--line);background:var(--soft);font-size:.75rem;letter-spacing:.3em}.welcome-mark span{font:140px/1.2 Georgia,serif;color:var(--ink)}.page-heading,.section-heading{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:24px}.section-heading h2{margin:0}.course-list article{display:flex;justify-content:space-between;align-items:center;gap:24px;border-top:1px solid var(--line);padding:25px 0}.course-list article h3{margin-bottom:10px}.course-list article p{margin:0;max-width:650px}.course-list article>a{flex-shrink:0}.empty-state{background:var(--soft);border-left:3px solid var(--primary);padding:30px}.empty-state p{margin:0}.grid{display:grid;gap:24px}.grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}.author-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}.list{list-style:none;padding:0;margin:0}.job-list{max-height:580px;overflow:auto}.job-list li{padding:18px 0;border-top:1px solid var(--line)}.job-list p{font-size:.9rem}.workspace-links{display:flex;gap:30px;flex-wrap:wrap}.messages{list-style:none;padding:0;margin:0 0 25px}.messages li{padding:14px 18px;background:var(--soft);border-left:3px solid var(--ink);margin-bottom:10px}label{display:block;color:var(--text);font-size:.9rem;font-weight:600;margin-bottom:7px}input:not([type=radio]):not([type=checkbox]),textarea,select{width:100%;max-width:100%;padding:11px 13px;font:inherit;color:var(--text);background:#fff;border:1px solid #a9b7ad;border-radius:2px}input[type=radio],input[type=checkbox]{width:auto;margin-right:10px;accent-color:var(--primary)}textarea{resize:vertical}.helptext{display:block;font-size:.8rem;margin-top:6px}.errorlist,.error-note{color:#9c3128}.errorlist{padding-left:20px}.lesson-shell{display:grid;grid-template-columns:190px minmax(0,1fr) 250px;gap:20px}.lesson-shell .panel{padding:22px}.lesson-shell h1{font-size:2.2rem!important}.slide-body{white-space:pre-wrap;overflow-wrap:anywhere}.slide-link{display:block;width:100%;padding:10px;margin:0 0 8px;border:1px solid var(--line);background:transparent;text-align:left;font:inherit;font-size:.85rem;color:var(--ink)}.slide-link.current{background:var(--soft);border-color:var(--primary)}.slide-link.locked{color:var(--muted);border-style:dashed}.preview-slide{border-top:1px solid var(--line);padding:24px 0}.footer{display:flex;justify-content:space-between;gap:20px;padding-top:24px;padding-bottom:32px;border-top:1px solid var(--line);font-size:.8rem;color:var(--muted)}.skip-link{position:absolute;left:12px;top:-80px;background:white;padding:12px;z-index:100}.skip-link:focus{top:10px}details{margin-top:18px}summary{cursor:pointer}
/* Course, slide and quiz text may contain long domains, URLs or identifiers.
   Wrap without clipping, and let content-sized flex/grid items shrink. */
main{overflow-wrap:anywhere}
main .stack>*,main .course-list article>*,main .page-heading>*,main .section-heading>*,main .author-grid>*{min-width:0;max-width:100%}
@media(max-width:1050px){.lesson-shell{grid-template-columns:170px minmax(0,1fr)}.lesson-shell>aside:last-child{grid-column:2}.welcome-mark{right:0;width:170px}.welcome h1{max-width:65%}.welcome p{max-width:60%}}
@media(max-width:760px){.shell{padding-left:20px;padding-right:20px}.topbar{min-height:70px}.nav{display:none}.menu-toggle{display:inline-flex;padding:8px 12px;border:1px solid var(--line);background:none;color:var(--ink)}.mobile-nav{display:grid;gap:18px;padding:8px 0 24px}.mobile-nav a,.mobile-nav button{min-height:32px;text-align:left}.welcome{padding:8px 0 36px}.welcome-mark{display:none}.welcome h1,.welcome p{max-width:100%}.grid.two,.author-grid,.lesson-shell{grid-template-columns:1fr}.lesson-shell>aside:last-child{grid-column:auto}.lesson-shell>aside:first-child{order:2}.lesson-shell>section{order:0}.lesson-shell>aside:last-child{order:1}.panel{padding:20px}.page-heading,.course-list article{align-items:flex-start;flex-direction:column}.section-heading{align-items:flex-start}.section-heading h2{font-size:1.5rem}.footer{flex-direction:column;gap:8px}.workspace-links{gap:18px}main{padding-top:26px}.actions .button{min-height:48px}h1{overflow-wrap:anywhere}}

/* Shared learner UI: restrained navy/teal, consistent states and readable copy. */
.button:disabled{cursor:default;opacity:.5;background:var(--paper);color:var(--muted);border-color:var(--line)}
.nav a:hover,.nav button:hover,.mobile-nav a:hover,.mobile-nav button:hover{color:var(--primary)}
.course-list article h3 a:hover{color:var(--primary)}
.panel>.panel{border-color:var(--line)}
.messages li{background:var(--soft);border-left-color:var(--primary)}
input:not([type=radio]):not([type=checkbox]),textarea,select{border-color:#B5C9CD}